Method of making hollow metallic balls.



J. W. SGHATZ.

METHOD OF MAKING HOLLOW METALLIC BALLS.

APPLIGATION FILED MAR. 21, 1912.

Patented Sept.24,1912.

QWihmeoaca:

UNITED STATESPATENT OFFICE.

JOHN W. SCHATZ, OF POUGHKEEYSIE, NEW YORK, ASSIGNOB OI bNE-HALF TO HEB-HAN A. SCHATZ, OI POUGBKEEPSIE, NEW'YOBK.

METHOD 0! KING HOLLOW METALLIC BALLS.

Specification of Letters Intent.

Patented Sept. 24, 1912.

Application filed latch 21, 1918. Serial Io. 885,327.

To all'whom it may concern:

Be it'known that I, JOHN W. SCHATZ, a citizen of the United States, and a resident of the city of Poughkeepsie, county of Dutchess, and State of New York, have invented a new and Improved Method of Making Hollow Metallic Balls, of which the following is a full, clear, and exact description.

It is the purpose of this invention to pro duce hollow metallic balls by the practice of the process herein described, whereby the balls are made rapidly and perfectly and possess, when finished, unusual strength, because of the perfection of the welding operation resulting from the method of forming the blanks and the treatment applied to i 4 shown in Fig. 3; Fig. 5 illustrates in elevation a completed ball.

In the drawings I illustrate the dies diagrammatically only and omit entirely the press in which they are placed and by which they are manipulated in perfect alinement.

I also omit the conducting wires, etc., of the electric welding apparatus which I prefer to employ. I do this because these appliances form n0 essential part of the present invention and also because many forms'of them are now well known and in extensive use.

Referring to the drawings, 1 represents one of the blanks. It is preferably drawn up into cup shape, as shown, from'a flat disk of metal, usually sheet steel. Two of these blanks are used for each ball and in order that there may be an excess of metal to permit of the forcing together and upsetting of it at the welded joint between the two halves, one or both of them, preferably both, are made somewhat larger or deeper than would be a true semi-sphere, so

that when two of them are put togetherbase to base, they present a somewhat oblong appearance.

2, 2, represent the upper and lower dies. One of them is rigidly supported on the table of the press and the other is adapted to be forced toward the stationary one. Both may, however, be movable, if preferred. In each of these dies a cavity, 3, is accurately made, which is slightly less in size than that of half of the ball for which the dies are intended, but otherwise conforming in shape. This slight scantiness is provided, so that a little space 4 (see Fig. 3) may be left between the dies when they are brought together, into which the compressed metal may move during the welding operation. This is illustrated in Figs. 2 and 3. In- Fig. 2 the two blanks 1, 1, are shown base to base and each in its cavity 3, 3, in the respective dies. In Fig. 3 the heating and pressure has been accomplished and the metal which has been heated almost to the fusing point at the bases or rims of the blanks has been forced together and a little of the excess metal has been squeezed out into the space 4 between the dies, as seen at 5. The electric welding apparatus is so arranged and the heat so applied to the blanks that their bases or rims shall be heated very hot, as stated, almost to the fusing point, and the other parts of them more removed from the rims are heated to say a cherry red and since, as stated, the cavities in the respective .dies are accurately made and conform to the semispherical shape of the finished ball. when the pressure is applied, the oblong shape of the two half blanks is transformed into a true spherical shape, so that when the welded ball is removed from the dies, as. shown in Fig. 4, it is practically completed because it has already been given almost perfect spherical form and all that remains to be doneis to cut off the slight circumferential bur 5 and grind the ball, as usual, which finishes it as shown in Fig. 5.

Under the process described, a series of very valuable results are secured at a minimum of cost and they result not only in the production of superior balls, but also in very greatly decreasing the time required for' means whereby a most strong and reliable welding of the parts together results. i (b) The differential heating of the blanks, z'. 6.,

the rims or bases almost to the fusing point and the other parts of the blanks to less degrees of heat, is very easily attained by the electrical welding process without any increased cost and yet because of this difierem tial heating the less hot parts being supported by the dies will withstand the pressure to which they are subjected without buckling or collapsing and will powerfully force the highly heated rims ,of the blanks together, thus effecting a perfect welding of them. (0) Owing to the fact that the cavities in the dies are so shaped as to give to the welded ball a truly spherical shape, the single stepin the process of applying the pressure performs the dual functions of welding the blanks together and at the same time accurately shaping and largely completing the ball, and nothing remains to be done but to remove-the circumferential bur and grind or polish the ball.

It will be obvious-to those who are familiar-With such matters that certain of the details above described may be modified without departing from the essentials of the invention. I therefore do not limit myself to the details. The several steps in the process recited in the claim hereof I regard as essential, but not the specified detail of their accomplishment.

I claim as of my invention:

The described process consisting in supporting two substantially semi spherical hollow blanks in recesses slightly less than semi-spheres made in suitable dies, bringing .their rims together, heating the rims to welding heat and the other parts of the blanks to lower degrees of heat and then forcing the dies toward 'each other, so that the blanks are welded together and given a spherical shape.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN W. SCI-IATZ. Witnesses:

JOHN B. BALL, E. E. PERKINS- 

